JP5207452B2 - Pantograph and method for improving the following characteristics of pantograph - Google Patents

Description

  The present invention relates to a pantograph that collects current from a trolley line in an electric railway, and a method for improving the following characteristics of such a pantograph. In particular, the present invention relates to a pantograph and a method for improving the tracking characteristic of a pantograph that can provide good tracking characteristics in a wide frequency band even when the excitation frequency from the trolley line changes due to a change in the speed of the vehicle or the like.

  In current electric railways for business use, a method of sending electric power from a trolley line to a vehicle via a pantograph is common. The height of the trolley wire with respect to the vehicle body is not constant, for example, there is a height change (unevenness) according to the arrangement interval of hangers that support the trolley wire, etc. Will be subject to fluctuations. Here, if the sliding plate provided on the boat body does not follow the change in the height of the trolley line and a separation line is generated, a spark is generated between the sliding plate body and the trolley line. The wear and tear becomes a problem. Therefore, it is required for the pantograph that separation is not generated as much as possible by improving the following characteristic of the sliding plate body with respect to the trolley line.

Conventionally, the following techniques are known as techniques for improving the following characteristics of a pantograph with respect to a trolley line.
(1) Each boat body is elastically supported by a common support so that a plurality of boat bodies can vibrate independently of each other, and the resonance points of the elastic support systems of the boat bodies do not overlap each other. Shift (see, for example, Patent Document 1).
(2) A pair of front and rear hulls is provided to vary the mass of each hull, and the spring constants of the restoring springs provided at both ends in the vehicle width direction of each hull are different from front to back and left and right (for example, , See Patent Document 2).
(3) Provided with a drive mechanism that individually moves a plurality of hulls up and down individually, and by moving each hull up and down with a certain period of time from each other for a predetermined time, one of the hulls is always on a trolley line. It controls so that it may contact | connect (for example, refer patent document 3).
Japanese Patent Publication No.56-27042 JP 2006-174667 A Japanese Patent Laid-Open No. 54-20506

However, since the prior arts of the above-mentioned patent documents require a plurality of boat bodies, the structure of the pantograph becomes complicated and the weight increases. Furthermore, it is difficult to modify and apply existing pantographs.
Moreover, with the speeding up of electric railways, pantographs are required to exhibit good tracking characteristics in a wide speed range.

  The present invention has been made in view of the above-described problems, and has improved the following characteristics of the current collector sliding portion to the trolley wire in a wide range of vehicle speeds without causing complication of the pantograph, and An object of the present invention is to provide a method for improving the following characteristics of a pantograph.

In order to solve the above-described problems, a pantograph as a base of the present invention includes a current-collecting sliding portion that contacts a trolley wire, a support mechanism that supports the current-collecting sliding portion so as to be displaceable with respect to a vehicle body, and the support A variable spring element that can change a spring constant provided in a mechanism, and the spring constant of the variable spring element is changed according to a dominant frequency at which the trolley wire vibrates the current-collecting sliding portion when the vehicle is running And a control means.

As for the following amplitude characteristic with respect to the trolley line of the current collector sliding part of the pantograph, several peaks and valleys generally appear according to the frequency. The frequency of such peaks and valleys varies depending on the spring constant of the spring element that supports the current collector sliding portion.
According to the present invention, a frequency band in which a good tracking amplitude can be obtained by changing the spring constant of the variable spring element according to the dominant frequency at which the trolley wire vibrates the current collector sliding portion when the vehicle is running. Can be followed to improve the following characteristics of the pantograph. Accordingly, the following characteristics of the pantograph can be improved over a wide range of vehicle traveling speeds without complicating the structure of the pantograph, for example, by providing a plurality of boat bodies.

In the pantograph of the present invention, the control means increases the spring constant of the variable spring element in accordance with a change in the traveling speed of the vehicle.
That is, the dominant frequency at which the trolley wire vibrates the current collector sliding portion is substantially proportional to the traveling speed of the vehicle when the arrangement interval of hangers that support the trolley wire is substantially constant. On the other hand, by increasing (increasing) the spring constant of the spring element, the peak of the tracking amplitude characteristic can be shifted to the higher frequency side. Therefore, by increasing the spring constant according to the traveling speed of the vehicle, good tracking can be achieved. Amplitude characteristics can be obtained.
In this case, the spring constant of the spring element may be changed continuously or may be changed stepwise.

The pantograph of the present invention is an air spring in which the variable spring element has a gas chamber in which compressed gas is stored, and pressure variable means for changing the pressure of the compressed gas in the gas chamber according to the output of the control means. It can be set as the structure provided.
In the present specification, claims, etc., “air spring” is assumed to use gas (including other than air) as a compressed gas that generates a spring reaction force. The air spring is typically a rolling diaphragm type or an air cylinder type, but is not particularly limited thereto.
In this case, the spring constant of the air spring can be changed by increasing or decreasing the pressure of the compressed gas in the gas chamber.

  Here, the pressure variable means is provided in a high-pressure gas supply source that supplies a gas having a pressure higher than the pressure in the gas chamber of the air spring, and a pipe that communicates the high-pressure gas supply source and the gas chamber of the air spring. And a pressure regulating valve.

In the pantograph of the present invention, the variable spring element is an air spring having a gas chamber in which compressed gas is stored, and includes a volume variable means for changing the volume of the gas chamber in accordance with the output of the control means. can do.
In this case, the spring constant can be increased or decreased by increasing or decreasing the volume of the gas chamber.

Here, the volume variable means is connected to the gas chamber of the air spring via a pipe line, and a sub-gas which can select a state connected to or shut off from the gas chamber by a valve provided in the pipe line It can be set as the structure provided with a chamber.
In this case, the spring constant of the air spring can be varied in a wide range depending on the volume of the auxiliary gas chamber and the number of installed gas chambers.

Further, the volume variable means may be connected to the gas chamber of the air spring via a pipe line, and a volume variable gas chamber capable of continuously changing the volume may be provided.
In this case, fine control can be performed by continuously changing the entire air chamber volume and changing the spring constant of the air spring steplessly.

  In the pantograph of the present invention, the variable spring element includes a biasing force transmission member that transmits a biasing force of the variable spring element to the current collector sliding portion, and a biasing force transmission member that biases the biasing force transmission member in the trolley line direction. The first air spring and a second air spring that urges the urging force transmitting member in a direction substantially opposite to the first air spring may be provided.

In the pantograph of the present invention, the variable spring element may be formed of an elastic solid material, and may include an auxiliary spring that urges the current collecting sliding portion in substantially the same direction as the air spring.
In this case, a desired spring constant that cannot be obtained only by adjusting the gas pressure can be obtained by setting the auxiliary spring, and fail-safeness can be ensured when a failure occurs in the air spring.

A method for improving the following characteristics of a pantograph as a base of the present invention includes: a current collecting sliding portion that contacts a trolley wire; a support mechanism that supports the current collecting sliding portion so as to be displaceable with respect to a vehicle body; and A method for improving the following characteristics of a pantograph having a spring element that is provided and biases the current collecting sliding part in the direction of the trolley line, wherein the trolley line vibrates the current collecting sliding part when the vehicle travels The spring constant of the spring element is changed according to the dominant frequency.
In this case, the spring constant of the spring element can be increased in accordance with an increase in the traveling speed of the vehicle.

  The pantograph of the present invention includes a pipe line that communicates the pressure variable means and the gas chamber of the first air spring, and a pipe line that communicates the pressure variable means and the gas chamber of the second air spring. Each may be configured to be provided with a flow rate limiting unit.

  Here, the flow rate restricting unit includes general means for restricting the flow rate by generating a channel resistance (pressure loss) by, for example, making a channel cross-sectional area of a part of a pipeline smaller than other parts. . Such a flow restricting unit includes an orifice restrictor, a flow control valve, a porous restrictor, a venturi and the like.

In the above-described variable spring element, the setting of the pressure variable means is changed when the urging force transmission member is displaced from the neutral position as the variable spring element expands and contracts, and compressed gas is introduced into or discharged from the gas chamber of each air spring. In this case, there is a difference in the average gas pressure (steady gas pressure) through one stroke in each gas chamber, and the neutral position of the urging force transmission member may change. However, according to the present invention, by restricting the flow rate of the compressed gas between the pressure variable means and the gas chamber of each air spring, it takes some time after changing the setting of the pressure variable means. The internal pressure of the gas chamber can be changed. As a result, even if the set pressure of the pressure variable means is changed when the variable spring element is at a position other than the neutral position, the variable spring element expands and contracts until the pressure change in each gas chamber is completed. The steady gas pressure in the gas chamber is less affected by the timing of changing the setting of the pressure variable means. As a result, the steady gas pressures of the gas chambers can be made closer to each other, and the neutral position of the urging force transmission member can be maintained.
In the following description, the “neutral position” means a position where the pressures in the upper and lower gas chambers are balanced and the restoring force becomes zero.

  In the pantograph of the present invention, the pressure varying means can maintain the pressure between the pressure varying means and the flow rate restricting unit at a predetermined value even when the pressure of the gas chamber of each air spring is not changed. preferable.

  In this case, even if a steady gas pressure difference occurs between the gas chambers and the neutral position of the variable spring element is shifted, the difference in gas pressure is reduced while the variable spring element is in use (during a stroke). You can gradually correct and return the neutral position to the original position.

  The pantograph of the present invention is configured to include a conduit that communicates the gas chamber of the first air spring and the gas chamber of the second air spring, and a flow rate limiting portion provided in the conduit. be able to.

  According to the present invention, when the variable spring element is in a position other than the neutral position, the setting of the pressure variable means is changed, a difference occurs in the steady gas pressure in each gas chamber, and the neutral position of the variable spring element changes. Even in this case, the compressed gas flows from the high steady pressure side to the low steady pressure side through the conduit, and the steady pressure can be made uniform. At this time, by providing the flow restricting portion in the pipe line, the temporary pressure difference between the gas chambers of each spring generated by the stroke of the variable spring element is maintained, so that the effect as a spring can be secured.

  In the pantograph of the present invention, it is preferable that the pressure variable means is cut off from these gas chambers except when the pressure of the gas chamber of the first air spring and the gas chamber of the second air spring is changed.

  As described above, according to the present invention, the spring constant of the variable spring element that biases the current collector sliding portion in the direction of the trolley wire is changed according to the frequency at which the current collector sliding portion is excited by the trolley wire. By doing this, it is possible to improve the tracking characteristics of the pantograph by shifting the frequency band in which a good tracking amplitude is obtained.

<First Embodiment>
Hereinafter, a first embodiment of a pantograph to which the present invention is applied will be described with reference to the drawings. In the following description, the rail longitudinal direction (vehicle traveling direction) is the front-rear direction and the direction perpendicular to the rail longitudinal direction on the track surface is the left-right direction (vehicle width), as in the ordinary railcar technology. Direction), the direction perpendicular to the track surface is called the up-down direction.

FIG. 1 is a schematic front view of the pantograph of the first embodiment viewed from the traveling direction of the vehicle. Fig.1 (a) has shown the whole pantograph, FIG.1 (b) is the b section enlarged view of Fig.1 (a).
The pantograph 1 includes a boat body 10, a base frame 20, a frame body 30, and the like, and an air spring unit 100 is provided between the boat body 10 and the frame body 30.

The boat body 10 is a beam-like member extending substantially along the vehicle width direction, and includes a sliding plate body 11. The boat body 10 is a current collecting sliding portion referred to in the present invention.
The ground plate 11 is a plate-like member that comes into contact with the trolley wire (feeding line / overhead wire) T and slides with the trolley wire T to ensure electrical conduction when the vehicle is traveling. The ground plate body 11 is made of, for example, an iron-based or copper-based sintered alloy, or made of a carbon-based material. The trolley line T extends substantially along the traveling direction of the vehicle, but is arranged in a meandering manner within the effective width of the sliding plate body 11 in order to prevent local wear of the sliding plate body 11.
Further, the boat body 10 is provided with a connection stay 12 that protrudes downward from the boat body 10 and is connected to the air spring unit 100. The connection stays 12 are provided in a pair spaced apart in the vehicle width direction.

  The underframe 20 is a part that is fixed to the roof of the vehicle body and functions as the base of the pantograph 1. Further, an insulator 21 for insulation is provided between the underframe 20 and the vehicle body roof.

The frame body (support mechanism) 30 includes a link mechanism that supports the boat body 10 so as to be displaceable in the vertical direction with respect to the vehicle body. The frame body 30 can be in an elevated state in which the sliding plate body 11 is in contact with the trolley line T and a lowered state in which the sliding plate body 11 is separated from the trolley line T when the pantograph 1 is not used.
The frame 30 includes an upper frame 31, a lower frame 32, a hinge 33, a ceiling tube 34, and the like.

The upper frame 31 and the lower frame 32 are lever-like members that respectively constitute the upper part and the lower part of the frame body 30.
The hinge 33 connects the lower end portion of the upper frame 31 and the upper end portion of the lower frame 32 so as to be able to swing with each other.
The ceiling pipe 34 is connected to the upper end portion of the upper frame 31 and extends in a beam shape substantially along the vehicle width direction, and supports the boat body 10 via the air spring unit 100.
In addition, the frame body 30 includes a frame body biasing spring element (not shown) that biases the ceiling tube 34 in a direction in which the ceiling tube 34 is pushed up in the direction of the trolley line T.

The air spring unit 100 is a variable spring element (variable rigidity mechanism) that is provided between the connection stay 12 of the boat body 10 and the ceiling pipe 34 of the frame body 30 and that can change the spring constant.
The air spring unit 100 has a pair of rolling diaphragm type air springs opposed to each other with a piston 110 interposed therebetween. The air spring unit 100 includes a piston 110, an upper air spring 120, and a lower air spring 130.

FIG. 2 is a schematic cross-sectional view of the air spring unit 100. FIG. 2A shows a no-load (piston intermediate position) state, and FIG. 2B shows a state in which the piston 110 is pushed down by the downward input F through the flange portion 111.
The piston (biasing force transmission member) 110 is formed in a columnar shape, and is disposed so that the longitudinal direction thereof is substantially along the vertical direction. The upper end and the lower end of the piston 110 are inserted into the upper air spring 120 and the lower air spring 130, respectively, and are pressed by these air springs.
Moreover, the piston 110 is provided with a flange portion 111 projecting in a collar shape from the outer peripheral surface of the intermediate portion in the longitudinal direction. The connection stay 12 of the boat body 10 is fixed to the flange portion 111.

The upper air spring 120 is provided on the upper portion of the piston 110 and urges the upper end portion of the piston 110 downward.
The lower air spring 130 is provided at the lower part of the piston 110 and biases the lower end of the piston 110 upward.
The upper air spring 120 and the lower air spring 130 are provided with tanks 121 and 131, diaphragms 122 and 132, stoppers 123 and 133, respectively.

The tanks 121 and 131 are pressure vessels that store compressed air that is a working fluid of an air spring. The tanks 121 and 131 are formed in a cylindrical shape in which the central axis direction is substantially coincident with the piston 110 and is concentrically arranged. The upper end portion of the tank 121 and the lower end portion of the tank 131 are closed by a flat end surface.
The diaphragms 122 and 132 are rolling diaphragms formed by a film body made of an elastic material such as rubber. These diaphragms 122 and 132 close the lower end opening of the upper tank 121 and the upper end opening of the lower tank 131, respectively. Further, the central portions of the diaphragms 122 and 132 are in contact with the piston 110 in a state where the upper end portion and the lower end portion of the piston 110 are respectively wrapped, and transmit a repulsive force (biasing force) that generates compressed air to the piston 110. In addition, the space part obstruct | occluded by the tanks 121 and 131 and the diaphragms 122 and 132 becomes an air chamber filled with compressed air that is a working gas of each air spring. The compressed air in each air chamber is adiabatically expanded or compressed in accordance with the displacement of the piston 110.

  The stoppers 123 and 133 are members for holding the diaphragms 122 and 132 and restricting the deformation mode. Each of the stoppers 123 and 133 is a ring-shaped member that is attached to the lower end opening edge of the upper tank 121 or the upper end opening edge of the lower tank 131 so as to be substantially concentric with each tank. The inner peripheral surfaces of the stoppers 123 and 133 are arranged to face the outer peripheral surface of the piston 110 with a predetermined interval S therebetween. In this interval S, the ring-shaped part between the peripheral part and the center part of the diaphragms 122 and 132 is accommodated in a bent state.

The air spring unit 100 includes pressure varying means 140 described below.
FIG. 3 is a block diagram showing the configuration of the pressure varying means 140.
The pressure varying means 140 includes an air reservoir 141, pipe lines 142 and 143, proportional relief valves 144 and 145, a control device C, and the like.

The air reservoir 141 is a pressure vessel that is connected to a compressor (not shown) and stores compressed air used for vehicle power and control. The internal pressure of the air reservoir 141 is maintained at a state higher than the maximum internal pressure in the usage state of the tanks 121 and 131 of the air spring unit 100.
The pipe lines 142 and 143 connect the air reservoir 141 and the tanks 121 and 131 of the air spring unit 100.

The proportional relief valves 144 and 145 are provided in the middle of the pipe lines 142 and 143, respectively, and adjust the internal pressure of the tanks 121 and 131 of the air spring unit 100.
For example, when the internal pressure of the tanks 121 and 131 is lower than the target pressure set by current control, the proportional relief valves 144 and 145 introduce compressed air in the air reservoir 141 to increase the pressure to the target pressure. On the other hand, when the internal pressures of the tanks 121 and 131 are higher than the target pressure, the air in the tanks 121 and 131 is released from the air vent to the atmosphere and reduced to the target pressure.
The control device C includes a CPU that acquires information related to the traveling speed of the vehicle and controls the proportional relief valves 144 and 145 according to the traveling speed. A specific control method will be described in detail below.

Next, a pantograph control method (following characteristic improving method) in the present embodiment will be described.
This control method is intended to improve the following amplitude characteristic of the pantograph in a wide speed band of the vehicle. Here, the following amplitude refers to the maximum amplitude that can follow the trolley line without being separated when the current collector sliding portion of the pantograph is vibrated by the vertical displacement of the trolley line or the like when the vehicle is traveling. This following amplitude characteristic is a typical guideline for evaluating the current collection performance of the pantograph. As a method for numerically evaluating this, a simple spring-mass model can be used.

FIG. 4 is a diagram showing a spring-mass model used for evaluation of the tracking amplitude characteristic.
The following amplitude is a frequency response, and for example, when a pantograph slides on a rigid trolley wire having a height change in a sine wave shape of a predetermined period due to the arrangement interval of hangers, etc., it causes separation. This means the maximum amplitude of the trolley wire unevenness that can be run without any problems.

FIG. 5 is a graph showing an example of the following amplitude characteristic of the pantograph. The horizontal axis of the graph indicates the vibration frequency, and the vertical axis indicates the tracking amplitude. The tracking amplitude is large at a low frequency and tends to decrease as the frequency increases. However, the following amplitude does not simply decrease with respect to the frequency, but generally several peaks and valleys appear.
The frequency at which these peaks appear (dominant frequency) and the frequency at which the valleys appear are determined by the masses m ₁ and m ₂ and the stiffness k ₁ shown in FIG. Moreover, it can be considered that the frequency of the trolley line unevenness is determined by the appearance cycle of hangers and the traveling speed of the train. When the appearance period of the hanger is L and the traveling speed of the train is V, the frequency f of the trolley line unevenness is given by f = V / L.

  Therefore, if the frequency at which the peak with good tracking performance appears (the second dominant frequency) can be made to substantially coincide with the frequency determined by the uneven wavelength of the trolley wire caused by the hanger, etc. and the traveling speed of the train, the tracking amplitude characteristic is good. It is possible to travel in a state. However, since the speed of the train changes, it is difficult to maintain good characteristics over a wide speed range when using a pantograph with a narrow frequency band with good following amplitude characteristics as shown in FIG. Therefore, in the present invention, the following amplitude characteristic is changed in accordance with the traveling speed of the vehicle, which is a parameter correlated with the excitation frequency of the boat body by the trolley wire, and the good following amplitude characteristic is obtained at the speed at that time. The spring constant of the air spring unit 100 is changed under the idea of

In FIG. 4, m _p is the sum of the masses of the boat body 10, the sliding plate body 11, and the piston 110 of the air spring unit 100, and m ₂ is the mass of the frame body 30 and the like. Also represent the spring constant of the air spring unit 100 is a variable stiffness mechanism (stiffness) at k _1. Further, the frame body 30 is pushed up the air spring unit 100 in static pushing force _{F s.} c ₁ and c ₂ are attenuation constants. When the displacement of the mass point m _p , m ₂ is expressed as x ₁ , x ₂ (upward is positive) and the contact force of the trolley line T acting on the mass point m _p is Fc, the equation of motion of the vibration system of FIG. The following equation 1 is given.

The above Equation 1 can be expressed as a matrix as Equation 2 below.

Assume that the pantograph vibrates periodically at an angular frequency ω due to the trolley line irregularities. Since this vibration is caused by contact force fluctuations, the external force vector need only consider fluctuations from Fs, which is a DC component. Therefore, it can be expressed as the following Expression 3 using the fluctuation F ₁ of the external force.

Also, the displacement of each mass point can be expressed as in Equation 4.

Substituting Equation 3 and Equation 4 into Equation 2, the following Equation 5 is obtained.

Equation 5 represents the relationship between the contact force fluctuation and the mass point displacement of the pantograph. The condition that the pantograph does not derail is that the magnitude of the contact force fluctuation does not exceed the static lifting force Fs. Therefore, the maximum amplitude that does not cause separation, that is, the following amplitude, can be obtained by substituting F ₁ = Fs into Equation 3 and obtaining the absolute value of X ₁ represented by Equation 6.

Here, the angular frequency ω of the contact force fluctuation is expressed as in Expression 7 by the uneven wavelength L of the hanger or the like and the train traveling speed V.

FIG. 6 is a graph showing an example of changes in the tracking amplitude characteristics when the spring constant (rigidity) of the air spring unit 100 is changed.
In the calculation, each parameter was set as follows.
m ₁ = 10.3 (kg)
m ₂ = 11.2 (kg)
c ₁ = 50 (Ns / m)
c ₂ = 80 (Ns / m)
k ₀ = 14700 (N / m)
Fs = 50 (N)
L = 5 (m)

  The broken line in FIG. 6 plots the locus of the peak point when the spring constant of the air spring unit 100 is continuously changed. It can be seen from FIG. 6 that the train traveling speed at which the peak of the following amplitude characteristic appears is increased by changing the spring constant. Therefore, in the pantograph of the present embodiment, control is performed to increase the spring constant of the air spring unit 100 in accordance with an increase in train traveling speed.

Here, the spring constant k of the air spring unit 100 is expressed by the following formula 8 assuming that the change in the state of the internal air when the piston 110 is displaced is an adiabatic change.

However,
γ: Adiabatic index (about 1.4 for air)
A: Cross-sectional area of piston 110 P ₀ : Internal pressure of upper air spring 120 and lower air spring 130 in the initial state V ₀ : Volume of upper air spring 120 and lower air spring 130 in the initial state

Therefore, since the spring constant k of the air spring unit 100 is proportional to the internal pressure P ₀ of the upper air spring 120 and the lower air spring 130 in the initial state, the control device C of the pressure variable means increases the train traveling speed. Accordingly, the proportional relief valves 144 and 145 are controlled to increase the internal pressure P0, and when the vehicle is decelerated, the internal pressure P0 is reduced.
Such control for changing the pressure may be performed continuously according to a change in the vehicle speed, or may be performed stepwise.

According to the first embodiment described above, the following effects can be obtained.
(1) By increasing the internal pressure of the tanks 121 and 131 of the air spring unit 100 and increasing the spring constant in accordance with the increase in the train traveling speed, the peak of the following amplitude characteristic of the boat body 10 to the trolley line T is obtained. The frequency can be shifted in the higher direction. As a result, even when the traveling speed of the train changes in a wide range, it is possible to obtain a good tracking amplitude characteristic corresponding to each speed and reduce the occurrence of separation lines.
(2) Since there is no need to greatly change the structure of the pantograph, for example, by providing a plurality of hulls, the structure of the pantograph is simplified, and it is easily applied to existing pantographs with relatively small modifications. be able to.
(3) By using an air spring for urging the boat body 10, the spring constant can be easily changed by adjusting the internal pressure by controlling the current of the proportional relief valve. Moreover, since the compressed air used as a working fluid can utilize what is used for the control of a vehicle, etc., it can be easily applied to the existing railway vehicle.

<Second Embodiment>
Next, a second embodiment of the pantograph to which the present invention is applied will be described with reference to FIG. FIG. 7 is a block diagram showing the configuration of the volume varying means in the second embodiment of the pantograph to which the present invention is applied. In each embodiment described below, the same parts as those in the previous embodiments are denoted by the same reference numerals, description thereof is omitted, and differences are mainly described.
The pantograph of the second embodiment is provided with a volume variable means 150 described below instead of the pressure variable means 140 in the first embodiment.
The same volume variable means 150 is provided in the upper air spring 120 and the lower air spring unit 130 of the air spring unit 100, respectively. The volume varying means 150 changes the air chamber volume of the air spring in stages by switching the communication or blocking between the tanks 121 and 131 of each air spring and the plurality of sub tanks 151, thereby changing the spring constant of the air spring unit 100. To change.

The volume varying means 150 includes a sub tank 151 (151a, 151b...), A pipe line 152, a valve 153, and the like.
Sub tank 151, a plurality of sub-tanks 151a having a volume _V 1, _{V 2} · · respectively, consists 151b · ·.

One end of the pipe line 152 is connected to the tank 121 of the upper air spring 120 or the tank 131 of the lower air spring 130, and the other end branches to each sub tank 151 (151 a, 151 b...). Are connected to each.
The valve 153 is provided at each branch portion of the pipe line 152 connected to each sub tank 151 (151a, 151b,...). The valve 153 switches between the state where each of the sub tanks 151 (151a, 151b,...) Communicates with the tank 121 or the tank 131 and the state where the sub tanks 151 (151a, 151b,.

Here, when the volume in the initial state of the tanks 121 and 131 is V ₀ , assuming that the volume in the pipe line 152 is small enough to be ignored, when the valve 153 of the sub tank 151a is opened, total air chamber volume corresponding to V ₀ (the denominator of the right side) is increased to _V 0 + _{V 1,} the spring constant is reduced to the original _{V 0 / (V 0 + V} 1) times. Accordingly, the spring constant of the air spring unit 100 can be changed by switching between communication and blocking of the sub tank 151 with the tanks 121 and 131.

Also, the number of sub-tanks 151 to be operated can be changed by opening the valves 153 of the plurality of sub-tanks 151 at the same time or changing the combination of the open valves 153 (combination of the sub-tanks 151 communicated). Adjustments can be made.
Also in the second embodiment described above, the same effect as in the first embodiment can be obtained.

<Third Embodiment>
The third embodiment of the pantograph to which the present invention is applied includes both the pressure variable means 140 of the first embodiment and the volume variable means 150 of the second embodiment.
FIG. 8 is a block diagram showing the configuration of the pressure varying means 140 and the volume varying means 150 in the third embodiment.
According to the third embodiment, in addition to the effects of the above-described embodiments, the spring constant can be changed more finely by controlling the air chamber volume and the internal pressure of each air spring of the air spring unit 100, respectively. Can do.

<Fourth Embodiment>
The fourth embodiment of the pantograph to which the present invention is applied is provided with a volume variable means 160 described below instead of the volume variable means 150 in the third embodiment.
FIG. 9 is a block diagram showing the configuration of the pressure varying means 140 and the volume varying means 160 in the fourth embodiment.

The volume changing means 160 includes an air cylinder 161 that is provided in each of the upper air spring 120 and the lower air spring 130 of the air spring unit 100 and communicates with the tanks 121 and 131 via pipe lines.
The air cylinder 161 is obtained by inserting a piston that is movable along the cylinder axis direction into a cylinder formed in a substantially cylindrical shape. The piston is driven by an actuator (not shown) controlled by the control device C, and the internal volume can be continuously changed by moving in the cylinder. In the present embodiment, the substantial air chamber volume of each of the air springs 120 and 130 is obtained by adding the volume in the air cylinder 161 to the volume of the tanks 121 and 131. Therefore, the spring constant of the air spring unit 100 can be changed by moving the piston in the air cylinder 161 to change the internal volume.

If the piston of the air cylinder 161 is moved and the volume is increased, the internal air is adiabatically expanded and the pressure is lowered. If the volume of the air cylinder 161 is decreased, the pressure is increased. In this case, the piston driving amount is set in consideration of the change in pressure, or the pressure variable means 140 is used to adjust the air spring pressure of the air springs 120 and 130 so that no unnecessary change occurs. It is preferable.
According to the fourth embodiment described above, in addition to the effects of the third embodiment described above, the springs of the air spring unit 100 are changed by continuously changing the air volume of the air springs 120 and 130. Since the constant can be changed continuously (steplessly), the spring constant can be controlled more precisely.

<Fifth Embodiment>
The fifth embodiment of the pantograph to which the present invention is applied includes an air spring unit 200 described below instead of the air spring unit 100 of the first embodiment.
FIG. 10 is a schematic cross-sectional view of the air spring unit 200. FIG. 10 (a) shows a no-load state, and FIG. 10 (b) shows a state where the piston 110 is pushed down by the downward input F. ing. The upper air spring 120 and the lower air spring 130 of the air spring unit 200 include auxiliary springs 124 and 134, respectively.
The auxiliary springs 124 and 134 are metal compression coil springs arranged substantially concentrically with the axis of the piston 110. The upper end portion of the auxiliary spring 124 is in contact with the upper end surface of the tank 121. Further, the lower end portion of the auxiliary spring 124 presses the upper end portion of the piston 110 via the diaphragm 122. The auxiliary spring 134 has a lower end contacting the lower end surface of the tank 131 and an upper end pressing the lower end of the piston 110 via the diaphragm 132.

Here, assuming that the spring constants of the auxiliary springs 124 and 134 are k _coil , the spring constant of the air spring unit 200 is expressed by the following Expression 9.

According to the fifth embodiment described above, in addition to the same effects as those of the first embodiment described above, even when the desired spring constant (rigidity) cannot be obtained only by controlling the air pressure and volume, By setting the spring constants of the auxiliary springs 124 and 134, the degree of freedom in setting the spring constant of the air spring unit 200 as a whole can be improved. Further, even when a failure occurs in each of the air springs 120 and 130 of the air spring unit 200, fail-safe property can be ensured.
Note that the air spring unit 200 of the present embodiment can also be applied as an alternative to the air spring unit 100 of the second to fourth embodiments described above.

<Sixth Embodiment>
The sixth embodiment of the pantograph to which the present invention is applied includes an air spring unit 300 described below, instead of the air spring unit 100 of the first embodiment.
11 is a schematic cross-sectional view of the air spring unit 300. FIG. 11 (a) shows a no-load state, and FIG. 11 (b) shows a state where the piston 110 is pushed down by the downward input F. ing.
The piston 110 of the air spring unit 300 includes a rod 112 described below instead of the flange portion 111 in the first embodiment.

The rod 112 is formed so as to protrude from the upper end surface and the lower end surface of the piston 110, and the tip thereof penetrates the openings formed in the end surfaces of the tanks 121 and 131, from the upper end portion and the lower end portion of the air spring unit 300. It sticks out.
The end surfaces of the tanks 121 and 131 are provided with seals 121a and 131a that support the rod 112 so as to be movable along the longitudinal direction and prevent leakage of compressed air.
The air spring unit 300 is incorporated in a pantograph with the tanks 121 and 131 fixed to one side of the boat body 10 and the frame body 30 and the tip of the rod 112 fixed to the other side.
In the sixth embodiment described above, the same effect as that of the first embodiment described above can be obtained.
The air spring unit 300 of this embodiment can also be applied as an alternative to the air spring unit 100 of the second to fourth embodiments described above.

<Seventh Embodiment>
The sixth embodiment of the pantograph to which the present invention is applied includes an air cylinder type air spring unit 400 described below in place of the rolling diaphragm type air spring unit 100 of the first embodiment.
12A and 12B are schematic perspective views of the air spring unit 400. FIG. 12A shows a no-load state, and FIG. 12B shows a state where the piston 420 is pushed down by the downward input F. ing.
The air spring unit 400 includes a cylinder 410, a piston 420, a rod 430, an upper air chamber 440, and a lower air chamber 450.

  The cylinder 410 is formed in a cylindrical shape, and the cylinder axis thereof is arranged substantially along the vertical direction. The upper and lower ends of the cylinder 410 are closed by a flat end surface, and an opening into which the rod 430 is inserted is formed on this end surface. The opening is provided with sealing means that allows the rod 430 to move in the axial direction while maintaining airtightness with the outer peripheral surface of the rod 430.

The piston 420 is formed in a disc shape, and is inserted into the cylinder 410 so as to be movable along the axial direction of the cylinder 410. Sealing means for maintaining airtightness with the inner peripheral surface of the cylinder 410 is provided on the outer peripheral edge of the piston 420.
The rod 430 is formed to protrude from the upper surface and the lower surface of the piston 420, and the upper end portion and the lower end portion thereof are disposed to protrude from the upper and lower end surfaces of the cylinder 410.

The upper air chamber 440 and the lower air chamber 450 are formed in regions above and below the piston 420 inside the cylinder 410, respectively.
And each pipe line 142,143 of the pressure variable means 140 similar to 1st Embodiment is connected to these upper side air chambers 440 and the lower side air chamber 450, respectively.
In the seventh embodiment described above, the same effect as that of the first embodiment described above can be obtained.
Note that the air spring unit 400 of the present embodiment can also be applied as an alternative to the air spring unit 100 of the second to fourth embodiments described above.

<Eighth Embodiment>
The eighth embodiment of the pantograph to which the present invention is applied includes a one-push type air spring unit 500 described below instead of the double-push type (opposing type) air spring unit 100 of the first embodiment. Yes.
FIG. 13 is a schematic cross-sectional view of the air spring unit 500.
The air spring unit 500 has a configuration in which the upper air spring 120 is omitted from the air spring unit 100 of the first embodiment, and the piston 110 is biased only by the lower air spring 130.
Therefore, the conduit of the pressure varying means 140 is connected only to the tank 131 of the lower air spring 130.
The spring constant of the air spring unit 500 is expressed by the following formula 10.

In the eighth embodiment described above, it is necessary to perform control in consideration of the displacement of the neutral position of the piston 110 due to a change in pressure or the like, but the structure of the air spring unit is simplified to reduce the weight of the pantograph. It can be downsized.
The tank 131 of the lower air spring 130 can be provided with the volume variable means 150 and 160 described above alone or together with the pressure variable means 140.

<Ninth Embodiment>
The ninth embodiment of the pantograph to which the present invention is applied includes an air cylinder type air spring unit 600 described below, instead of the rolling diaphragm type air spring unit 500 of the eighth embodiment.
14A and 14B are schematic perspective views of the air spring unit 600. FIG. 14A shows a no-load state, and FIG. 14B shows a state in which the piston 620 is pushed down by the downward input F. ing.
The air spring unit 600 includes a cylinder 610, a piston 620, a rod 630, and an air chamber 640.

  The cylinder 610 is formed in a cylindrical shape, and its cylinder axis is arranged substantially along the vertical direction. The lower end of the cylinder 610 is closed by a flat end face. Further, the upper end portion of the cylinder 610 is an opening and is open to the atmosphere.

The piston 620 is formed in a disc shape, and is inserted into the cylinder 610 in a state where it can move along the axial direction of the cylinder 610. Sealing means for maintaining airtightness with the inner peripheral surface of the cylinder 610 is provided at the outer peripheral edge of the piston 620.
The rod 630 is formed to protrude from the upper surface of the piston 620, and the upper end portion thereof is disposed to protrude from the upper end portion of the cylinder 610.

The air chamber 640 is formed in a region below the piston 620 inside the cylinder 610.
Then, the respective pipelines such as the pressure variable means 140 and the volume variable means 150, 160, which are the same as those in the eighth embodiment, are connected to the air chamber 640, respectively.
Also in the ninth embodiment described above, the same effects as those in the eighth embodiment described above can be obtained.

(Other embodiments)
In addition, this invention is not limited only to above-described embodiment, Various application and deformation | transformation can be considered. For example, the following embodiments applying the above embodiment can be implemented.
(1) The shape and configuration of the pantograph and the air spring unit are not limited to the above-described embodiments, and can be changed as appropriate. For example, the pantograph may include a movable sliding plate that can move relative to the hull. In this case, a variable spring element may be provided between the boat body and the sliding plate. Further, as the air spring, for example, a bellows type other than the rolling diaphragm type and the air cylinder type may be used.
(2) In each embodiment described above, the air spring unit uses air as the working gas, but working gas other than air, such as nitrogen gas, may be used.
(3) In each of the above-described embodiments, the spring constant of the variable spring element is changed according to the traveling speed of the vehicle. For example, even if the traveling speed of the vehicle is constant, current collection is performed due to a difference in hanger interval or the like. When the frequency at which the sliding portion is vibrated changes, the spring constant may be changed according to the vibration frequency.
(4) Although each embodiment mentioned above uses the current control by a proportional relief valve as a pressure variable means, it is not restricted to this, You may control a pressure by another method. For example, a pressure sensor may be provided in the air chamber or the communication portion of the air spring to perform feedback control based on the actual pressure value.

  By the way, in the above-mentioned air spring, the internal pressure of the tank of the upper and lower air springs is adjusted to support the boat body with variable rigidity with respect to the vehicle body. When the internal pressure of the tank is increased or decreased according to the change in the traveling speed of the train while the piston of the air spring is vibrating, if the piston can be increased or decreased when the piston is in the neutral position, the steady gas in each tank The pressure can be kept uniform. However, if the piston is increased or depressurized when the piston is in a position other than the neutral position, a difference may occur in the steady gas pressure in each tank, and the neutral position of the piston may change.

15A and 15B are diagrams showing displacement of the piston. FIG. 15A shows a state where the piston is in the neutral position, and FIG. 15B shows a state where a downward force F is applied to the piston.
FIG. 16 is a diagram for explaining an example of the passage of time of the piston displacement, the proportional relief valve command pressure, the upper tank, the lower tank, and the restoring force when the internal pressure of the tank is changed when the piston is in the neutral position.
FIG. 17 is a diagram for explaining an example of the passage of time of piston displacement, proportional relief valve command pressure, upper tank, lower tank, and restoring force when the internal pressure of the tank is changed when the piston is in a position other than the neutral position.

First, the case where the internal pressure of the tank is increased when the piston 110 is in the neutral position will be described with reference to FIGS.
As shown in FIG. 16A, the piston 110 normally reciprocates with a substantially constant amplitude and frequency. When the piston 110 is in the neutral position (when the piston displacement is 0) (time t ₀ ), a pressure increase command (1 → 2 in this example) is sent from the control device to the proportional relief valves 144 and 145 of the pipe lines 142 and 143. When received, the proportional relief valves 144 and 145 are opened, and compressed air is introduced from the air reservoir 141 into the tanks 121 and 131 (see FIG. 16B). As shown in FIGS. 16C and 16D, the internal pressures of the upper and lower tanks 121 and 131 fluctuate in opposite sine waves according to the reciprocating motion of the piston. When the piston displacement is 0, that is, when the steady pressures of the upper and lower tanks 121 and 131 are the same (1 in this example), the steady pressures of the tanks 121 and 131 are commanded after the compressed air is introduced. The pressure increases to 2 (in this example 2). And it fluctuates in the shape of a sine wave corresponding to the reciprocating motion of the piston 110 around the boosted value. As a result, as shown in FIG. 16E, the absolute value of the restoring force of the piston 110 increases as the internal pressure increases, and the average value is zero.
In FIG. 15B, the restoring force is a force that causes the piston 110 to return to the original neutral position when the external force F is applied to the piston 110 and pushed downward by the distance x. It is the sum of opposing forces F1 and F2.

On the other hand, as shown in FIG. 17A, when the piston 110 is in the fluctuating position (1 in this example) (time t ₀ ), as shown in FIG. It is assumed that a boost command (1 → 2 in this example) is received by the relief valves 144 and 145 from the control device. At this time (time t ₀ ), as shown in FIGS. 17C and 17D, the internal pressure of the upper tank 121 is temporarily increased by the reciprocating motion of the piston 110 (1.25 in this example). The lower tank 131 is in a state where the internal pressure is temporarily lowered (0.75 in this example). When a pressure increase command is received in this state, the internal pressure of the upper tank 121 is increased from the temporarily increased value (1.25) to the command pressure (2) as shown in FIG. The internal pressure of the tank 131 is increased from the temporarily reduced value (0.75) to the command pressure (2) as shown in FIG. Thereafter, the internal pressures of the tanks 121 and 131 continuously change in a sine wave shape, but in the direction in which the internal pressure decreases in the upper tank 121 and in the direction in which the internal pressure increases in the lower tank 131. As a result, as shown in the state after command pressure reception (time t ₀ ) in FIGS. 17C and 17D, the average of the pressure in the upper tank 121 (steady pressure, 1.75 in this example), The average of the pressure of the lower part 131 (steady pressure, 2.25 in this example) is different. Then, as shown in FIG. 17 (E), the restoring force of the piston 110 increases in absolute value as the internal pressure increases, but the average value deviates from 0, and the piston 110 moves away from the neutral position. Reciprocates as the center.

  In such a case, the operation of the air spring may become unstable, or the neutral position of the piston may be different between the left and right air springs, and the pantograph may tilt or the trolley wire may be pushed up excessively.

Hereinafter, an example in which such an improvement is made to prevent the neutral position of the piston 110 from changing will be described.
<Tenth Embodiment>
The pantograph of the tenth embodiment is obtained by adding changes as shown in FIG. 18 to the pressure variable means 140 (see FIG. 3) in the first embodiment.
FIG. 18 is a cross-sectional view schematically illustrating an air spring unit according to the tenth embodiment.
FIG. 19 is a graph showing the time elapse of the piston displacement, the proportional relief valve command pressure, the upper tank, the lower tank, and the restoring force when the internal pressure of the tank is changed when the piston is in a position other than the neutral position in the air spring unit of FIG. It is a figure explaining an example.
In the pantograph of this embodiment, the throttles (flow restricting portions) between the proportional relief valves 144 and 145 and the respective tanks 121 and 131 in the pipe lines 142 and 143 between the upper and lower tanks 121 and 131 and the air reservoir 141. 148 and 149 are provided.
Here, the restriction means that a flow passage resistance (pressure loss) is generated and a flow rate is restricted by making a flow passage cross-sectional area of a part of a pipe line smaller than other portions. In addition to the restriction, a flow control valve, a porous restriction, a venturi, or the like can be used.

By providing such throttles 148 and 149, when the pressure increasing command is received by the proportional relief valves 144 and 145 from the control device (time t ₀ ) and the set pressure is changed, as shown in FIG. Then, the compressed air starts to be gradually introduced from the air reservoir 141 to the tanks 121 and 131, and the internal pressure (steady pressure) of the tanks 121 and 131 is changed over a certain period of time (time t ₁ ). Note that the proportional relief valves 144 and 145 are opened even after the boost command is received. That is, air is supplied or discharged so as to keep the pressure in the pipe line between the proportional relief valves 144 and 145 and the throttles 148 and 149 at the set pressure.
When the internal pressure of the tanks 121 and 131 is higher than the command pressure, the air in the tanks 121 and 131 is released from the air vent and the pressure is reduced to the target pressure.

That is, as shown in FIG. 19 (A), when the piston 110 is in the fluctuation position (1 in this example) (time t ₀ ), the upper tank 121 is moved as shown in FIGS. 19 (B) and (C). Even when the internal pressure of the lower tank 131 temporarily increases (1.25 in this example) (0.75 in this example), the internal pressure of the tanks 121 and 131 changes (steady state). The piston 110 reciprocates until the pressure change is completed (time t ₀ → t ₁ ), and as shown in FIGS. 19 (C) and 19 (D), both tanks finally Is a value increased by the boosted amount (steady increase). Then, as shown in FIG. 19E, the restoring force has an absolute value that is increased by the boosted amount, and the average value is zero.

  In this example, if the pressure between the proportional relief valves 144 and 145 and the throttles 148 and 149 is maintained at the target steady gas pressure, in addition to the above causes, the steady pressure between the tanks is constant. Even when the neutral position of the piston 110 shifts due to a difference in internal pressure, the neutral position can be gradually corrected while the piston 110 is in use (during a stroke), and the neutral position can be returned to the original position.

<Eleventh embodiment>
The pantograph of the eleventh embodiment is obtained by adding changes as shown in FIG. 20 to the upper and lower air springs 120 and 130 (see FIG. 3) of the air spring unit in the first embodiment.
FIG. 20 is a cross-sectional view schematically illustrating the air spring unit according to the eleventh embodiment. FIG. 21 is a diagram illustrating how the internal pressure of the tank is changed when the piston is in a position other than the neutral position in the air spring unit of FIG. It is a figure explaining an example of time passage of piston displacement, proportional relief valve command pressure, upper tank, lower tank, and restoring force when doing.
As shown in FIG. 20, the pantograph of this embodiment is provided with a pipe line 170 communicating with tanks 121 and 131, and a throttle 171 provided in the middle of the pipe line 170. The opening of the throttle 171 is set such that the difference between the internal pressure of the upper tank 121 and the internal pressure of the lower tank, which are temporarily generated during the normal stroke movement of the piston 110, is maintained, and the effect as a spring can be secured.

As shown in FIG. 21 (A), when the piston 110 is in the fluctuating position (1 in this example) (time t ₀ ), as shown in FIG. 21 (B), the proportional relief valve 144 of each pipeline, Assume that a boost command (1 → 2 in this example) is received from the control device at 145. These proportional relief valves 144 and 145 are closed after the introduction of compressed air. After the start of the introduction of compressed air, the internal pressure of the upper tank 121 is increased from the increased value (1.25 in this example) to the command pressure (2 in this example) as described with reference to FIG. The internal pressure is increased from the lowered value (0.75 in this example) to the command pressure (2 in this example). Thereafter, as described with reference to FIG. 17, the internal pressures of the tanks 121 and 131 continuously vary in the direction in which the internal pressure decreases in the upper tank 121 and in the direction in which the internal pressure increases in the lower tank 131. However, as shown in FIGS. 21 (C) and 21 (D), as time passes, compressed air flows from the high-pressure tank 121 to the low-pressure tank 131 through the conduit 170, and finally Specifically, the internal pressures of both tanks 121 and 131 become the same value increased by a steady pressure increase. As shown in FIG. 21E, the restoring force also has an average load deviated from 0 in the initial stage, but gradually becomes 0 with the passage of time.

  The pipe line 170 is provided with a throttle 171, and the compressed air does not flow from the high pressure side tank to the low pressure side tank at a stretch. Therefore, the temporary internal pressure of the upper tank 121 generated by the stroke of the piston 110 and the lower tank The difference in internal pressure 131 is maintained, and the spring constant of the variable spring element can be maintained.

It is the typical front view which looked at the 1st embodiment of the pantograph to which the present invention is applied from the direction of vehicles travel. FIG. 2 is a schematic cross-sectional view of an air spring unit provided in the pantograph of FIG. 1. It is a block diagram which shows the structure of the pressure variable means with which the air spring of FIG. 2 is equipped. It is a figure which shows the spring-mass point model used for evaluation of the following amplitude characteristic of a pantograph. It is a graph which shows an example of the following amplitude characteristic of a pantograph. It is a graph which shows an example of the change of the following amplitude characteristic at the time of changing the spring constant of the air spring unit of a pantograph. It is a block diagram which shows the structure of the volume variable means in 2nd Embodiment of the pantograph to which this invention is applied. It is a block diagram which shows the structure of the pressure variable means and volume variable means in 3rd Embodiment of the pantograph to which this invention is applied. It is a block diagram which shows the structure of the pressure variable means and volume variable means in 4th Embodiment of the pantograph to which this invention is applied. It is typical sectional drawing of the air spring unit in 5th Embodiment of the pantograph to which this invention is applied. It is typical sectional drawing of the air spring unit in 6th Embodiment of the pantograph to which this invention is applied. It is a typical see-through | perspective perspective view of the air spring unit in 7th Embodiment of the pantograph to which this invention is applied. It is typical sectional drawing of the air spring unit in 8th Embodiment of the pantograph to which this invention is applied. It is a typical see-through | perspective perspective view of the air spring unit in 9th Embodiment of the pantograph to which this invention is applied. FIG. 15A shows a displacement of the piston. FIG. 15A shows a state in which a downward force F is applied to the piston when the piston is in a neutral position. It is a figure explaining an example of time passage of piston displacement, proportional relief valve command pressure, an upper tank, a lower tank, and restoring force when changing an internal pressure of a tank when a piston is in a neutral position. It is a figure explaining an example of time passage of piston displacement, proportional relief valve command pressure, an upper tank, a lower tank, and restoring force when changing an internal pressure of a tank when a piston is in a position other than a neutral position. It is sectional drawing which illustrates typically the air spring unit which concerns on 10th Embodiment of the pantograph to which this invention is applied. In the air spring unit of FIG. 18, an example of the passage of time of the piston displacement, the proportional relief valve command pressure, the upper tank, the lower tank, and the restoring force when the internal pressure of the tank is changed when the piston is in a position other than the neutral position will be described. FIG. It is sectional drawing which illustrates typically the air spring unit which concerns on 11th Embodiment of the pantograph to which this invention is applied. In the air spring unit of FIG. 20, an example of the passage of time of piston displacement, proportional relief valve command pressure, upper tank, lower tank, and restoring force when the internal pressure of the tank is changed when the piston is in a position other than the neutral position will be described. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pantograph 10 Ship body 11 Ground plate body 12 Connection stay 20 Base frame 21 Insulator 30 Frame body 31 Upper frame 32 Lower frame 33 Hinge 34 Ceiling pipe 100 Air spring unit 110 Piston 111 Flange 120 Upper air spring 130 Lower air spring 121, 131 Tank 122, 132 Diaphragm 123, 133 Stopper 140 Pressure variable means 141 Air reservoir 144, 145 Proportional relief valve 148, 149 Restriction 170 Pipe line 171 Restriction C Controller

Claims (11)

A current collector sliding part in contact with the trolley wire;
A support mechanism for supporting the current collector sliding portion so as to be displaceable with respect to the vehicle body;
A variable spring element capable of changing a spring constant provided in the support mechanism;
Control means for changing the spring constant of the variable spring element in accordance with a dominant frequency at which the trolley wire vibrates the current collector sliding part during travel of the vehicle;
A pantograph with a,
The variable spring element is an air spring having a gas chamber in which compressed gas is stored;
Pressure varying means for changing the pressure of the compressed gas in the gas chamber according to the output of the control means;
Further, the variable spring element is
An urging force transmission member for transmitting the urging force of the variable spring element to the current collector sliding portion;
A first air spring that biases the biasing force transmitting member in the direction of the trolley wire;
A pantograph comprising a second air spring that urges the urging force transmitting member in a direction substantially opposite to the first air spring. The pressure adjusting means is provided in a high-pressure gas supply source for supplying a gas having a pressure higher than the pressure in the gas chamber of the air spring, and in a pipe line that connects the high-pressure gas supply source and the gas chamber of the air spring. The pantograph according to claim 1 , further comprising a valve. The variable spring element is an air spring having a gas chamber in which compressed gas is stored,
3. The pantograph according to claim 1, further comprising volume changing means for changing a volume of the gas chamber in accordance with an output of the control means. The volume variable means is connected to the gas chamber of the air spring via a pipe line, and has a sub gas chamber that can select a state connected to or shut off from the gas chamber by a valve provided in the pipe line. The pantograph according to claim 3 . 4. The pantograph according to claim 3 , further comprising a volume-variable gas chamber that is connected to the gas chamber of the air spring via a pipe line and capable of continuously changing the volume. 5. The variable spring element is formed by a solid material having elasticity, claims 1-5 any one, characterized in that it comprises an auxiliary spring that urges the current collector sliding portion in substantially the same direction as the air spring Pantograph as described in. A flow rate restricting section is provided for each of a pipe line that communicates the pressure variable means and the gas chamber of the first air spring, and a pipe line that communicates the pressure variable means and the gas chamber of the second air spring. Is provided, The pantograph according to any one of claims 1 to 6 . Said pressure varying means, according to claim 7 be other than when the pressure change of the gas chamber of each air spring, characterized by maintaining a pressure between the pressure changing means and said flow restriction at a predetermined value Pantograph as described in. A conduit for communicating the gas chamber of the first air spring and the gas chamber of the second air spring;
A flow restriction provided in the pipe;
The pantograph according to any one of claims 1 to 8 , wherein the pantograph is provided. 10. The pantograph according to claim 9 , wherein the pressure varying means is cut off from these gas chambers except when the pressures of the gas chambers of the first air spring and the gas chamber of the second air spring are changed. . A method for improving the following characteristics of a pantograph according to any one of claims 1 to 10 ,
A method for improving the following characteristic of a pantograph, wherein the spring constant of the spring element is changed in accordance with a dominant frequency at which the trolley wire vibrates the current-collecting sliding portion when the vehicle is running.